Apparatus for the continuous development of light sensitive papers



Aug. 11, 1959 R s JACOBS 2,898,835

APPARATUS FOR T'HE' CONTINUOUS DEVELOPMENT OF LIGHT SENSITIVE PAPERS Filed Get. 8, 1956 2 Sheets-Sheet 1 Aug. 11, 1959 R. s. JACOBS 2,898,835

. APPARATUS. FOR THE CONTINUOQS DEVELOPMENT OF LIGHT SENSITIVE PAPERS Filed Oct.- 8, 1956 '2 Sheets- Sheet 2 United States Patent APPARATUS FOR THE CONTINUOUS DEVELOP- MENT OF LIGHT SENSITIVE PAPERS Ridley Saul Jacobs, London, England, assignor to The Nig Manufacturing Company Limited, London, England, a company of Great Britain Application October 8, 1956, Serial No. 614,595

6 Claims. (Cl. 95-94) This invention relates to apparatus for the continuous development of light sensitive materials, such as diazo type papers, by means of vapour such as ammonia vapour.

According to the present invention, in apparatus for continuous development of light sensitive materials, there is provided an ammonia tank, from which heated vapour is delivered to a developing chamber, through which the material to be developed is guided by an endless belt, such as a rubber blanket, one wall of said chamber forming a bafiie for vapour delivered to said chamber through an inlet from a delivery duct between the tank and developing chamber, the battle and belt converging together in the direction of feed of paper, the bafile also having a series of orifices therein through which vapour from the developing chamber flows back into the ammonia tank, whereby the flow of vapour occurs in a closed circuit.

The duct may terminate in a box-like chamber, communication between which and the developing chamber is formed by a continuous transverse slot in a common wall between said box-like and developing chambers, which wall forms the baffle which directs the vapour at an acute angle to the direction of feed of paper.

The slot in the baffle may be interrupted to form a number of apertures to establish desired communication between the box-like and developing chambers.

One form of apparatus according to this invention is illustrated in the accompanying drawings in which Figure 1 is a diagrammatic general view of the apparatus, and Figure 2 a perspective cut-away view of the ammonia tank.

Referring to the drawings, the apparatus comprises a generally L-shaped ammonia tank, shown at 1 (Figure 2), which is divided by walls 2 into an ammonia vapour storage chamber 3 and a duct in the form of an ammonia vapour delivery box-like chamber 4. Built on to the vapour storage chamber 3 is a pump housing 5 in which is housed a centrifugal pump shown generally at 6. The fan sucks vapour from the chamber 3 through the fan eye to feed it under pressure through an opening 7 in the rear wall of the chamber 4. The opposite Wall of the said delivery chamber 4 is formed with a continuous slot 8, which forms the delivery outlet for the ammonia vapour to a developing chamber 9 formed by one wall of the said chamber and by a rubber blanket 11 which is driven in a closed path over rollers 12, and over which blanket the paper to be developed is fed, the blanket and its rollers being housed within a casing 10. The common wall 14 of the box-like chamber 4 and developing chamber 9 converges from the outlet 8 adjacent which the paper is fed to the chamber 9 in the direction of feed of paper, the said outlet 8 being so arranged that the vapour is fed at an acute angle to the said direction of paper feed.

The vapour storage chamber 3 is formed with series of It will be ice in addition to the wall which forms the bafiie 14, and the casing 10, by overhanging parts 15 of the wall of the chamber 4.

16 indicates a trough into which ammonia liquid is fed 5 in known manner to provide vapour in the chamber 3.

Paper which has been developed, as it leaves the blanket 11, is picked up by a travelling belt 17 to deliver it in known manner to an outlet 18 or 19 as desired.

The ammonia vapour may be heated either in the chamber 3, at the suction side of the pump 6 or in the box-like chamber 4.

It will thus be apparent that, when paper to be developed is fed to the blanket 11 and this is driven, and the pump 6 is in action, ammonia vapour is sucked from the chamber 3, delivered through the opening 7 to the box-like chamber 4, and out therefrom in a heated condition through the slot 8, into the developing chamber 9 in which it flows evenly over the paper to be developed, and finally returns through the orifices 13 to the storage chamber 3.

With apparatus constructed in accordance with this invention it will be appreciated that a rapid stream of heated ammonia vapour can be directed at any desired velocity evenly across the surface of the paper to be developed, to assure a constantly uniform mixture, whilst the vapourising and/or heating can be carried out at almost any point in the closed circuit of vapour, for example either inside or outside the tank 1. Hence very rapid speeds of development are obtained and diazo type prints from all kinds of materials, such as thin papers or tracing cloths, can be developed without sticking or frequent distortion, and the dangers of condensation can be readily controlled.

What is claimed is:

1. Apparatus for the continuous development of light sensitive materials such as diazo type papers, including an ammonia vapour storage chamber, a developing chamber, delivery duct means between said ammonia vapour storage chamber and said chamber, through which duct means heated vapour from said ammonia vapour storage chamber can pass to said developing chamber, a movable endless belt forming one wall of said developing chamber, said belt constituting a moving guide for the material to be developed, a bafile constituted by another wall of said developing chamber, which battle guides the vapour delivered to said developing chamber through the duct means from said ammonia vapour storage chamber, said bafiie and said endless belt converging in the direction of feed of the material and said duct means opening into said developing chamber remote from the end thereof toward which said baffle and said endless belt converge, and a series of orifices in said bafiie through which vapour from the developing chamber can flow back into the ammonia vapour storage chamber, so that the flow of vapour occurs in a closed circuit.

2. Apparatus as claimed in claim 1 in which the duct means includes a box-like chamber, communication between which and the developing chamber is formed by a continuous transverse slot in the bathe which forms a common wall between said box-like and developing chambers which baflle directs the vapour at an acute angle to the direction of feed of paper.

3. Apparatus for the continuous development of light sensitive materials such as diazo type papers, including an ammonia vapor storage chamber, a developing chamber, delivery duct means: between said ammonia vapour storage chamber and said developing chamber, through which duct means heated vapour from said ammonia vapour storage chamber can pass to said developing chamber, a movable endless belt forming one wall of said developing chamber, said belt constituting a moving guide for the material to be developed, a bafile constituted by another wall of said developing chamber, which bafile guides the vapour delivered to said developing chamber through the duct means from. said ammonia vapour storage chamber said baflle and said endless belt converging in the direction-of feed of the material and said duct means opening into said developing chamber remote from the end thereof toward which said bafiie and said endless belt converge, and means for returning vapour from said developing chamber to said ammonia vapour storage chamber.

4. Apparatus for the continuous development of light sensitive materialsuch as diazo type papers, comprising atank, wall means forming within said tank a vapour storage chamber and a vapour delivery chamber, a developing chamber having a wall common with and dividing it from said vapour delivery chamber, an endless movable belt forming a-wall of said developing chamber opposite said common wall, said developing chamber having an inlet end and an outlet end, said endless belt providing a movable support for feeding the paper to be developed from said inlet end to'said outlet end, said common wall and said endless belt converging toward 4 said outlet end, said common wall having an opening adjacentsaid inlet end for continuously supplying vapour from said delivery chamber to said developing chamber, and means for returning vapour from said developing chamber to said storage chamber.

5. Apparatus as claimed in claim 4 wherein said opening forms the sole means for supplying vapour from said delivery chamber to said developing chamber and is so shaped as to deliver vapours entering said developing chamber at an acute angle to the direction of feed of the paper.

6. Apparatus as claimed in claim ,4 wherein said means for returning vapour from said developing chamber to said storage chamber is constituted by a series .of orifices in said common wall.

References Cited in the file of this patent FOREIGN PATENTS 115,003 Sweden Sept. 18, 1945 614,931 Great Britain Jan. 13, 1949 477,896 Canada Oct. 16, 1951 

